18816857 has 4 divisors (see below), whose sum is σ = 18860160. Its totient is φ = 18773556.

The previous prime is 18816851. The next prime is 18816869. The reversal of 18816857 is 75861881.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18816857 - 2⁶ = 18816793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18816851) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20993 + ... + 21870.

It is an arithmetic number, because the mean of its divisors is an integer number (4715040).

Almost surely, 2^18816857 is an apocalyptic number.

It is an amenable number.

18816857 is a deficient number, since it is larger than the sum of its proper divisors (43303).

18816857 is an equidigital number, since it uses as much as digits as its factorization.

18816857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43302.

The product of its digits is 107520, while the sum is 44.

The square root of 18816857 is about 4337.8401307563. The cubic root of 18816857 is about 265.9800284627.

The spelling of 18816857 in words is "eighteen million, eight hundred sixteen thousand, eight hundred fifty-seven".